Thomas K. Miwa

Jojoba oil wax esters and derived fatty acids and alcohols: Gas chromatographic analyses

HCl-catalyzed ethanolysis followed by saponification readily surmounts the resistance of long chain wax esters to direct hydrolysis by alkali. Additionally, choosing ethyl instead of methyl esters allows baseline separations between long-chain alcohols and corresponding esters in gas liquid chromatographic (GLC) analysis of total alcohol and acid components before saponification. Liquid wax esters were analyzed on a temperature-programmed 3% OV-1 silicone column. Geographical and genetic effects on the variability of jojoba oil composition were investigated with five different seed samples. Major constituents in jojoba seed oil from shrubs in the Arizona deserts, as indicated by GLC analyses of oil, ethanolysis product, isolated fatty alcohols and methyl esters of isolated fatty acids, were C40 wax ester 30%, C42 wax ester 50% and C44 wax ester 10%; octadecenoic acid 6%; eicosenoic acid 35%, docosenoic acid 7%, eicosenol 22%, docosenol 21% and tetracosenol 4%. Oil from smaller leaved prostrate plants growing along California’s oceanside showed a slight tendency toward higher molecular size than oils from the California desert and Arizona specimens. The wax esters are made up of a dispro-portionately large amount of docosenyl eicosenoate and are not a random combination of constituent acids and alcohols.Lunaria annua synthetic wax ester oil was used as a model for evaluating the analytical procedures.

Jojoba oil analysis by high pressure liquid chromatography and gas chromatography/mass spectrometry

Two analytical procedures for determining com-positions of jojoba liquid wax esters are described and compared. One, the more tedious, involves separation of wax ester homologs by high pressure liquid chro-matography followed by determination of the acid and alcohol moieties from each homolog. The second allows rapid determination of wax ester composition by gas Chromatographic separation of hydrogenated jojoba wax esters according to chain length, followed immediately by ancillary mass spectrometric identifi-cation of the acid and alcohol moieties. Double bonds in the alkyl chains in jojoba liquid waxes were almost exclusively (98%) ω-9, when examined by gas chro-matography/mass spectrometry (GC/MS) and ozonolysis/GC/MS.

Structural determination and uses of jojoba oil

The predominating molecular species in jojoba oil iscis-13-docosenylcis-11-eicosenoate (erucyl jojobenoate), ranging from 31% to 45% of the extracted seed oil. Other alcohol/acid combinations contribute to the C42 molecular chain length so that this fraction constitutes a low of 41% to a high of 57% of the total wax esters. The positions of the exclusivelycis ethylenic bonds in the alcohol and acid moieties of the wax esters are 99% ω-9 and 1% ω-7. Only 2% of the alcohol and acid moieties were saturated when analyzed after saponification of the oil. Triglycerides were detected by gas chromatography in all of the more than 200 natural jojoba oil samples tested, a few of which had substantially more than the normal 1%. Among the many uses of jojoba oil cited here, the two most promising are the sulfurized oil as extreme-pressure/extreme-temperature lubricant additive and the natural or refined oil formulated into cosmetic products.

Extreme—Pressure lubricant tests on jojoba and sperm whale oils

Laboratory and simulated in-use lubricant tests were performed on sulfurized jojoba oil and on reference sulfurized sperm whale oil. Data from these comprehensive tests indicated sulfurized jojoba oil prepared from heat-treated filtered oil to be comparable or superior to sulfurized sperm whale oil as an extreme-pressure additive for motor oils, gear lubricants, and automotive transmission fluids.

Gas chromatograms of synthetic liquid waxes prepared from seed triglycerides of limnanthes, crambe and lunaria

Compositions of synthetic liquid waxes derived from erucic-containing seed oils vary considerably. These differences, when determined by gas chromatography, allow “fingerprint” identification of the source of oil.

Fatty acid composition of oil in snow crab (Chionoecetes opilio) by gas chromatography/mass spectrometry.

The hepatopancreatic fatty acid extract of the snow crab contains a high percentage (26%) of odd-carbon-numbered fatty acids and a substantial quantity (29%) of methyl-branched fatty acids, as indicated by gas chromatography/mass spectrometry (GC/MS) and gas liquid chromatography (GLC). A wide distribution in chain length of the fatty acids (C10 to C26) and in positional isomers of the linear monoenes are also indicated by GC/MS.

X-ray study of hydrogenated jojoba wax

Abstract and summaryCrystallographic analysis of hydrogenated jojoba wax ester shows the crystal structure to be monoclinic with orthorhombic perpendicular, 0⊥, chain packing. Cell dimensions are: a=4.99, b=7.44, c=55.2Å, β=90°. A larger secondary unit cell is observed and identified as permitting the hydrocarbon ester chains freedom of rotation. Hydrogenated jojoba was ester is crystallographically similar to polyethylene.

Brassidic acid: Preparation from erucic acid and mechanism of elaidinization

Brassidic acid was prepared by elaidinization of 95% erucic acid with 4 mole % nitrous acid at 70 C for 30 min, followed by crystallization from 95% ethanol. Yield was 70%, and purity was 96–97% by gas liquid chromatography and thin layer chromatography. The isomerization reaction was monitored by IRtrans absorption for optimal reaction rate and yield. There was no migration of the double bond. The NMR spectrum of thetrans protons was wide and complex with a chemical shift of 5.34 δ. The nitrous acid elaidinization, generally explained as a free radical process, is believed to be induced initially by the nitrogen dioxide anion (nitrite) and followed immediately by complex formation between the excited triplet anion and the olefin. The complex rotates to the opposite geometric configuration driven by a spin-orbital coupling process.

Preparation and evaluation of surface-active brassylic acid-ethylene oxide adducts

AbstractBoth liquid and solid surface-active adducts of brassylic (tridecanedioic) acid were prepared by potassium hydroxide-catalyzed addition of ethylene oxide gas to the molten acid. The number-average molecular weights